Difference Between Bromine and Bromide

Bromine vs Bromide | Br vs Br-

The elements in the periodic table are not stable except the noble gases. Therefore, elements try to react with other elements to gain the noble gas electron configuration to achieve stability. Likewise, bromine also has to get an electron to achieve the electron configuration of the noble gas, Krypton.  All metals react with bromine, forming bromides. Bromine and bromide has different physical and chemical properties due to the change of one electron.


Bromine is an element in the periodic table which is denoted by Br.  It is a halogen (17th group) in the 4th period of the periodic table. The atomic number of bromine is 35; thus, it has 35 protons and 35 electrons. Its electron configuration is written as [Ar] 4s2 3d10 4p5. Since the p sub level should have 6 electrons to obtain the Krypton, noble gas electron configuration, bromine has the ability to attract an electron. Bromine has a high electronegativity, which is about 2.96, according to the Pauling scale. The atomic weight of bromine is 79.904 amu. Under room temperature 79.904 exists as a diatomic molecule (Br2). Br2 is a Red-brown color liquid. Bromine has a melting point of 265.8 K and a boiling point of 332.0 K. Among all the bromine isotopes, Br-79 and Br-81 are the most stable isotopes. 79Br present in 50.69 % and 81Br present in 49.31%. Bromine is slightly soluble in water but soluble well in organic solvents like chloroform. Bromine has 7, 5, 4, 3, 1, -1 oxidation states. Chemical reactivity of bromine lies between that of chlorine and iodine. Bromine is less reactive than chlorine but more reactive than iodine. Bromine produces the bromide ion by taking up one electron. Therefore, bromine participates in ionic compound formation easily. Actually in nature bromine exists as bromide salts instead of Br2. Bromine has the ability to oxide the anions of elements which are located below bromine in the periodic table. However, it cannot oxidize chloride to give chlorine. Bromine can be produced by treating bromide rich brines with chlorine gas, or else by treating HBr with sulfuric acid, bromine gas can be produced. Bromine is widely used in industry and chemical laboratories. Bromide compounds are used as gasoline additives and for pesticides. Bromine can also be used as a disinfectant in water purification.


Bromide is the resulted anion when bromine abstracts an electron from another electropositive element. Bromide is represented by the symbol Br-.  Bromide is a monovalent ion with -1 charge. Therefore, it has 36 electrons and 35 protons. The electron configuration of bromide is [Ar] 4s2 3d10 4p6. Bromide exists in ionic compounds such as sodium bromide, calcium bromide and HBr. Bromide also exists naturally in water sources.


What is the difference between Bromine and Bromide?

• Bromide is the reduced form of bromine. Bromide has 36 electrons compared to 35 electrons of bromine, and both have 35 protons. Therefore, bromide has a -1 charge whereas bromine is neutral. 

• Bromine is more chemically reactive than Bromide.

• Bromide has achieved the krypton electron configuration, therefore, stable than the bromine atom.